Improvement in ore-roasting furnaces



'Unrrn IMPROVEMENT IN ORE-ROASTING FURNACES.

Specification forming part of Letters Patent No. 9135!, dated May 29,1877; application filed May 23,1876.

To all whom it may concern:

Be it known that I, HORATIO G. LIVER- MORE, of the city and county ofSan Francisco, State of California, haveinvented an ImprovedOre-Roasting Furnace; and I do hereby declare thefollowing descriptionand accompanying drawings are sufficient to enable any person skilled inthe art or science to which it most nearly appertains to make and use mysaid invention without further invention or experiment.

My invention relates to certain improvements in furnaces for roastingores. It is especially useful in connection with furnaces which areintended to extract quicksilver from its ores, and I have shown it asapplied to a furnace for which Letters Patent were issued to me'November9,1875, No. 169,713. It consists in the employment of a secondary orsupplemental fire, which heats the ore from be-' low the floor, overwhich it passes.

Referring to the accompanying drawing, Figure 1 is a longitudinalvertical section of my furnace. Fig. 2 is a transverse vertical sectionand Fig. 3 shows a portion of the orefloor with the fire-space beneath.I

A represents the body of my furnace, which is usually built, forconvenience and economy, upon a hill-side, so as to save the expense ofa large body of masonry. This furnace has its floor B built at anyincline which will allow the ore to flow by gravitation, if notinterrupted, as described in my former patent. The floor may be made ofiron plate, fire-tile, fire-brick, or any suitable substance, andinterrupting dams or abutments C may be placed across the floor, which,for convenience in handling the ore, is divided by longitudinalpartitions into channels. The fire-place D furnishes the heat, whichpasses up through the ore-chamber and roasts the ore, as described in myformer patent.

In order to assist in the roasting and expedite the process, I havefound it desirable to admit heat beneath the floor B from a supplementalfire-place, E, as shown in the figures. This is most economically doneby forming a series of channels, F, beneath the floor, corresponding inposition to the longitudinal channels above the floor. The heat isadmitted to these channels by passages from the fire-place E, and isallowed to pass out at the upper end into an escape-flue, Q, from whichit is conveyed into chamber G, to dry the ore in trays before thislatter is fed to the furnace proper. Suitable openings and dampers (notshown) are made opposite, or in aline with, these lower fire-lines, forthe purpose of regulating the heat and cleaning the passages. A currentof fresh furnace-flame is introduced into the ore-chamber about half-waybetween the fire-place and the escape-flue, through a flue, K, toincrease the heat and expedite the roasting by adding new flame toassist in burning any gases or carbon which may have become reduced intemperature. The mercuryvapors that are evolved by the action of thefurnace flames and gases upon the exposed ore pass to the dome-chamberS, situated above the upper part of the inclined floor, and thencethrough the side passages g, made in the side walls of the furnace, intothe fume-chamber G. The waste-heat of the calcined ore is utilized, andany remaining fumes it may contain are collected by side fines S, whichconvey them from chamber T into chamber R, and thence by the passage ginto the fume-chamber G. From the fume-chamber Gr the mercurial vaporsand hot air pass directly to the condensers H, of which as many areemployed as may beneeded.

From my method of building my furnace, the condensers will be built upona level with, or above, the feed-hopper I, and, as most of the ore ismore or less wet, I utilize the heat of the fumes in the condensers byspreading the ore upon their tops J and that of the furnace to dry,after which it can be readily fed into the hopper of the furnace.

As the construction of my furnace necessitates the pulverizing orbreaking of all the ore into small pieces, it will only be necessary toprovide machinery for this purpose; but most of the cinnabar minesproduce from onehalf to two-thirds, and often more, of the ore in thisfine condition, so that the expense will be comparatively small, and Iam thus enabled to avoid all the expense of mechanical means ofelevating devices for bringing the ore to the furnace, and even thevacuum or blast apparatus generally necessary can be dispensed with. v

The calcined ore, after reachingthe bottom of the roasting-sole, passesthrough suitable openings t into the chamber T, from which it may bewithdrawn, when desired.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-- 1. The inclined floor B, allowing the ore tomove over its surface by gravitation, and provided with the interruptingdams or abutments G, in combination with the channels F and thesupplemental fire-place E, substantially as described.

2. In combination with the inclined floor B, provided with theinterrupting-dams G, of the channels or chambers F, fire-place E, andfirethe roasting-chamber midway of its length,

substantially as and for the purpose specified.

4. The combination, with the inclined floor B and channels or chambersF, of the fireplace D, fire-place E, and flue K, substantially as andfor the purpose set forth.

HORATLO e. LIVERMORE.

Witnesses GEO. H. STRONG, CHAS. G. PAGE.

